1. Field of the Invention
The present invention relates to a scroll-type compressor, and more particularly to a sealing apparatus for restraining a compressed fluid in compression chambers of such a compressor from being leaked in which a stationary scroll is elastically supported at upper and lower portions thereof by means of elastic supporting members, thereby being easily applied to the scroll-type compressors regardless of sizes of the compressors.
2. Description of the Prior Art
With reference to FIG. 1, which shows a conventional scroll-type compressor for compressing, expanding or pumping fluids, for example, a refrigerant gas, the scroll-type compressor is provided with a hermetic shell 1, a compressing part 2 and a driving motor part 3, each being enclosed in the shell 1. In addition, a fluid passage for guiding the low pressure fluid, which is subjected to be compressed, to compression chambers 12 is provided to the compressor. The fluid passage includes a suction pipe 4 penetrating a side wall of the shell 1 and communicating with an external device, for example, an evaporator (not shown) of a refrigerator. On the other hand, there is a discharge pipe 11 provided at an upper end of compressor in order to guide the compressed fluid of high pressure from the compression chambers 12 to another external device, for example, a condenser (not shown) of the refrigerator.
The compressing part 1 of the compressor generally comprises a stationary scroll 5, an orbiting scroll 6 interleaved with the stationary scroll 5, a crankshaft 7 driving the orbiting scroll 6 in order to cause the scroll 6 to orbit and a main frame 8 for supporting the crankshaft 7 and the orbiting scroll 6. The stationary scroll 5 is intergrally provided with a wrap 5a having a convolution in the form of an involute or a combination of involutes and arcs, while the orbiting scroll 6 is intergrally provided with a wrap 6a having the same shape as that of the wrap 5a of the stationary scroll 5 but with the opposite direction of convolution. The wraps 5a and 6a of the scrolls 5 and 6 are interleaved with each other in order to define the compression chambers 12 therebetween.
Additionally, an Oldham coupling 9 is disposed between the orbiting scroll 6 and the main frame 8, thereby supporting the orbiting scroll 6 to be restrained from freely rotating. The crankshaft 7 has at the upper end thereof an eccentric shaft pin 7a which is connected to a downwardly extending hollow shaft of the orbiting scroll 6 by means of an eccentric busing 10 interposed therebetween. Thus, upon being driven by the crankshaft 7, the orbiting scroll 6 performs orbital motion about a point without rotation, thereby progressively decreasing the volumes of the compression chambers 12 between the wraps 5a and 6a, thus compressing the fluid in the chambers 12. Upon being compressed, the compressed fluid in the chambers 12 is discharged from the compressor through the discharge pipe 11.
At this time, the orbiting scroll 6 may wobble upwards and downwards due to a pressure difference between the inside and the outside of the compression chambers 12 so that minute radial clearances C and C' (see FIG. 2) may be formed between the scrolls 5 and 6, that is, between the ends of the wraps 5a and 6a and the bottom surfaces of the opposite scrolls 5 and 6. Therefore, there may occur a radial leakage of the compressed fluid in the compression chambers 12 through the radial clearances C and C'. Thus, the known scroll-type compressor generally provided with sealing members for restraining the radial leakage of the compressed fluid through the radial clearance will be described hereinafter.
As shown in FIG. 2 which is an enlarged sectional view showing the part "A" of FIG. 1, a fitting slit 5b, 6b of a predetermined depth is formed at the end of each wrap 5a, 6a in order to vertically receive elastic tip sealings 13, 13', thereby accomplishing the sealing members having a relatively simple structure. In orbital motion of the orbiting scroll 6, the tip sealings 13, 13' elastically expands and contracts depending upon the downward and upward wobbling of the orbiting scroll 6 in order to compensate for the radial clearances C and C' between the scrolls 5 and 6, thereby restraining the radial leakage of the clearances C and C'.
However, the above sealing members generally need to be made of a material having a good consume resistance, a good lubrication. Thus, the known sealing members for the scroll-type compressor have a disadvantage in that there is a considerable difficulty in selecting the materials of the sealing members. In addition, the fitting slits 5b and 6b are generally machined by an end mill machining, respectively, and the wraps 5a and 6a each is generally formed as having a relative narrow width so that the known sealing members have another disadvantage in that the fitting slits 5b and 6b need to be elaborately machined. Furthermore, the known sealing members have another disadvantage in that it may be impossible to machine the fitting slits 5b and 6b due to narrow wraps 5a and 6a in case of small size compressor.